To learn whether smooth communication is maintained among employees in some corporations, each employee wears a recording device (such as a microphone) to continuously record the voice of the employee. The continuous recording of the voice of each employee may pick up conversation voices in a variety of communications, including conversation voices face to face in a conference or chatting (also referred to as voice data), and telephone conversation voices. The voice data continuously recorded may be used to learn who converses with who for how long, and to study whether smooth communication is achieved among the employees.
The related art technique described above is disclosed in Japanese Laid-open Patent Publication No. 2010-266522.